The invention therefore relates in general to a treatment for printing a surface with an ink.
In spite of the significant growth in the digitization of printable documents and their accessibility on screens where they are easily viewed, no tangible decrease in the consumption of paper for printing such documents has been observed. Studies show that users still rely on hardcopy printouts in order to read documents.
To take environmental questions into consideration, proposals for the reuse of printed paper concern the nature of the ink used for printing. The goal is an ink that can be erased (rendering the paper blank once again) by a thermal and/or chemical treatment.
Document U.S. Pat. No. 5,922,115 proposes such an ink, which is erased when it is added to a reagent that causes the color to fade at a temperature of about 140° C. However, the reagent proposed in this document is costly and the paper used must be of a special design to enable it to withstand temperatures as high as 140° C.
In addition, a method for photocatalysis of the ink is known from document EP-2110417, but this method requires about 16 hours to obtain a blank page.
Also, such methods are not reversible. The ink is erased with no possibility of its reappearing. It may be advantageous in certain applications, particularly those related to security, to cause the printing to be visible once again.
The invention improves this situation.